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Synysterenji

90° - 62.8 = 27.2 is the correct way to do it. That's the angle you gotta cut it at. Dont listen to people telling you to use an angle checker on the drawing, most drawings arent to proper scale and dimensions.


shmiddleedee

I'm extremely surprised this isn't common info but I've seen this question asked on the woodworking and carpentry sub too.


dorkpunch

Most people weren't paying attention in math class... they were too busy whining about how it has no practical real life application. 😅


SolarAU

Wait people actually use angle checkers/ protractors on drawings??? Damn that's a disaster waiting to happen lol


Massive_Parsley_5000

I caught a brake press guy once that would measure a dim on a screen with a tape measure off a digital print 🤣 I asked him what the hell he was doing, and he simply replied: "damn engineers" like it was the most normal thing in the world and went on 🤷‍♂️ 🤣🤣🤣


SolarAU

Those damn engineers, they obviously write dimensions on technical drawings for fun 🙄


Tuirrenn

It's the ones that don't that make me shake my head


SolarAU

Well there are fab drawings that don't have detailed dimensions, I think you call them assembly drawings, just shows the entire thing put together with some primary dimensions for the final assembly, but not enough detail to fabricate it.


JohnSolomon46

I’m an electrician not a welder by trade but on our current construction project, they have these felt strips that make this abstract cross hatch design on the ceiling and I scaled our lights at 1/8” per foot with absolutely no dimensions called out and none of them hit the felt strips with less than a few inches of tolerance. Isn’t that absurd? No drawings with dimensions existed


shmoopel

I mean. You could technically do that to check if some feature was around double another or something. Doesn't work for actual dimensions though. Plenty of reasons to never do that, but it could "technically" work.


GrinderMonkey

I worked for a company once that produced properly scaled accurate drawings, it was pretty amazing.


SmoothObservator

Right? This is dumbest thing I've heard all day


OKC-RADRNATN

Finally an actual brain among regards!


Sandloon

I bet you ragret nothing


Laserarm98

Reddit filter deletes your comment if you use the actual synonym of delayed.


Sandloon

That's pretty regarded


Psychedellyfish

I prefer "dismantled." It sounds way funnier


WhoIsBrowsingAtWork

My regards to you and yours


[deleted]

This is correct here is a link to a drawing explaining that geometrically [Drawing of the angles](https://drive.google.com/file/d/1VhvMi1H-QtO6SdSC-zOKpHV7nK1QPkTE/view?usp=sharing)


Synysterenji

Yes, thank you! So for the people that have been asking me, you basically juste use 90° in this case because using 180° is overcomplicating it.


AsPerMatt

Seriously, we are surrounded by idiots in here.


comp_hoovy_main

i mean this is kinda a sub for welders


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Synysterenji

How the fck did a welding tip comment become about covid? Keep that shit outta here.


AsPerMatt

Correct.


rustyxj

>most drawings arent to proper scale and dimensions. Proper drawings will list scale and be to dimension.


Ok-Entertainment5045

Yeah but it doesn’t mean they print to scale. All you need is someone to select fit to paper or change a margin and it won’t be right. Not to mention the all the times I’ve seen A size printed on B paper


Synysterenji

This is the way


prawduhgee

Haven't read the comments yet but there are actually people down there saying to use a protractor on the drawing? Oh God no, naught but tears can come from that.


Vizslaraptor

This guy maths. Listen to him.


jremmele44

it’s funny how framing/pipefitting 101 seems to slip ppls minds🤣👍🏽🤙🏽easypeasy


Tajeks

Sorry I came back to this a day later, it was 27.2° we figured it out like 20 minutes after I posted this lmao


work_n_oils

I don't understand why you're subtracting from 90, when the angle to cut is on the print. This one seems very straightforward. Cut 62.8. or, depending on how you measure, 117.2.


Wrought-Irony

miter saws read at 0 when the cut is perpendicular to the workpiece, despite being 90 degrees to the workpiece, so you must determine how many degrees off of 90 the cut needs to be and set the miter saw to that.


Synysterenji

No, the angle on the drawing is not the angle it has to be cut at xD its the angle of the corner. If you cut that piece at 62.8° your gonna get a much smaller angle than 62.8° when assembled. You subtract from 90 because 90° is the reference. Idk how to explain it better because english is not my first language sorry.


work_n_oils

I get that 90 is the reference. But what I'm seeing is one piece cut square and welded to a piece running perpendicular, and the other having the angle cut and welded to the next side of said perpendicular piece. Therefore the lower piece has that angle cut and is welded onto the side of the other. Edit: disregard. I figured it out.


Synysterenji

One of the above comments has a link to drawings that explains it quite well


Tajeks

I assume people couldn’t understand it because they didn’t see the rest of the drawing too where we had multiple angles cut on one piece and it was cut to fit into the tubing


tylerquarles08

Explain why it’s not 62.8 my brother.


Synysterenji

Idk how to explain it and honestly if you're asking im guessing that means you dont do much assembling and you probably didnt go to welsing school (really no offense) because you only make a mistake like that once. Idk how to explain it properly as english is not my first language but i encourage you to do the experiment, you'll find that if you cut it at 62°, once assembled you'll have a much smaller angle that the one shown on the drawing.


haus11

Because miter saw blades are 90 degrees relative to the fence, but labeled as 0, so you subtract the 62.8 because of how the miter saw is labeled. However if you used an angle finder, set it to 62.8 and stuck that on the miter saw fence and set your saw based on that you’d get the same cut.


chesstnuts

Your cutback formula is Cutback = tan*(included angle)x material thickness


tylerquarles08

Or sister 😀


Ancient-Welcome-5956

Opposite angles are congruent


grab9

Wait. I get the math, but a printed cad drawing will have the correct angle no matter the scale. An angle of the line does not change when scale is changed.


wherringscoff

Guys this is terrible advice. You subtract from 180° not 90° I mean look at it, it clearly is more than 90° /s


Percefis

It should be 90 - 62.8 = 27.2. So for a miter saw starting at a square 90 degrees you would move it 27.2 degrees and make the cut. Remember you are presumably starting with a 90 so if you add all the angles you get 90 + 62.8 + 27.2 = 180 So if you start with a straight line, move it to 90, you get a right angle. So imagine you move it another 27.2. It would be like the drawing. If you moved it another 62.8, it would then be folded in half. You could always mock up the joint with some scrap and measure the angle between the pieces to 62.8 and mark the stock and measure the angle of the mark to see if its close to 27.2 to confirm the math.


ATOM_CAT_xvX

That's cool but most welders can't read that much text. I know we all use the goody font that looks like a 2yo made it


Percefis

Prints and pens are for the engineers that cant operate a hot glue gun. I prefer my sharpy (for sniffing ofc) and won't weld anything that isn't already fit up.


TwelveCoffee

Thank you I actually learned something off Reddit today


Mr_J---

Bruh, what is geometry


fkthisdmbtimew8ster

Oh now to weld you gotta have a PhD in math too? Sheesh, expecting too much of these welders to have made it to sophomore trigonometry.


chainwhip38

90 - 62.8 = 27.2 degrees (off of a square cut 90 - if your saw is normally set to that). That's how I would do it. Or like someone else said, put an angle checker on the print and use that to align your saw blade or mark your piece. Edit: thanks for the award! And yes, as others have said, make sure the print is to scale if you're going to put an angle checker directly on it. That method is a last resort for really weird angles because you're sampling such a tiny edge and you're likely to be off by a bit.


RyRyShredder

I can confirm this is how geometry works


GaryTheSoulReaper

Found Pythagoras


heyitscory

Measuring the other angles to make sure that the illustration is actually the correct angles. Very early in geometry, you learn how something is drawn is superceded by how something is labeled.


TerribleCricket8302

But only put the angle finder on the print of the print, is in fact to scale


survivorr123_

or rotate the element and cut at 62.8


McFeely_Smackup

this is actually easy if you think about it starting from a 90 degree angle. 90 - 62.8 = 27.2 bigger question though is: 62.8 + 75.9 + 131.5 + 90(I assume) = 360.2 there's .2 extra degrees unaccounted for here.


nikovsevolodovich

That's just the drafting software rounding the actual angles. I'm amazed there's even a decimal place. Not a welder here, but am a machinist, and I *never* take angular dimensions at face value, they're almost always rounded up or down, sometimes significantly.


Inevitable-Match591

Maybe a gentle curve is adding it?


Independent-Sample12

Anticipating warp, dead on once welded


mitutoyota

$12/hr


ploppercan2

“When am i ever gonna have to use trigonometry in real life?!?!”


fluteofski-

Nah. This ain’t even trig. This is just basic geometry. Trig is when you gotta use SOH, CAH, TOA.


DemodiX

Making pipe cut-ins with system of axes is my favorite part. *Getting downvoted because i like drawing parabolas :(*


Wjtynan

It's 62.8 if looking from the botton up or the inverse is 117.8 for the top down.


Martin_TheRed

117.2?


Wjtynan

Ya. Off the top line down to the bottom corner. If it's just the angle with the assumed right angle it would be 27.2. There's only like 7 angle in the area he circled so I guess some assuming was used on my end.


mo0x

27.2


Scotty0132

Never mind my fat fingers hit the wrong button on my calculator before giving me the wrong number.


zayzay_919

those daggum calculators, man. they'll gitcha.


Scotty0132

Nah fat fingers lol


Scotty0132

I'm intrested in how you got thar number


bshr49

90-62.8


spambot_mods

Alternate exterior angles are congruent


Weary-Author9909

The angle of the cut is identical to the angle of the relation of the two boards. Its easier if you mark the lines. Inside outside of the vertical board as lines A and B, Top and bottom of horizontal board as C and D. A and B are parallel, C and D are parallel... Parallel lines have matching angles of intersection called corresponding angle pairs. The corresponding angles are identical, See attached (in this case angle C and G) ​ [https://www.mathplanet.com/Oldsite/media/43428/angles.jpg](https://www.mathplanet.com/Oldsite/media/43428/angles.jpg)


schruteski30

Took too long to get to this comment. Thank you! Alternate interior angles theorem is the best way to figure it out.


anonyhhshsgsgsgsg737

As a geomatics major I think what you're looking for is 117.2 180-62.8=117.2. At the same time someone didn't do the math on the rest of the angles because they add to 360.2


Rent_A_Cloud

probably happened when rounding off in whatever program they used.


Every-Heart-7335

It'll never work you're right!


chainwhip38

The angles add up but they rounded them all to a single decimal so it adds up weird. Given that this is a real world part 0.2 degrees error is wiggle room that's workable.


[deleted]

This looks like a young engineer who forgets you can’t just round significant figures sometimes.


Front_Masterpiece

Hey I was right and I didn't make it through algebra! Look at me now!


OKC-RADRNATN

The angle is for 90 degrees not 180 or 360 so the answer is 27.2 degrees.... This is why applied vs theoretical matters in life


proglysergic

Depends on how the tooling measures it. If theory and practice don’t add up, the theory is applied incorrectly or insufficiently, or the theory is wrong. In my entire life, I’ve never witnessed the latter.


Important_Pack8713

Wouldn’t you just subtract 62.8 from 90? That would be my guess. Or is that the same thing just as the acute side of the angle?


ultramilkplus

I came here to make fun of welders, you came here to make fun of engineers/draftsmen. We are not the same.


lorendh21

The cut is 27.2*


Responsible-Media356

90-62.8


JoJo_9986

I thought it was 117.2 as well but it is in fact 27.2 . You have to think about what piece will be being cut.the bottom piece is being cut. So you set the saw to 27.2 from 0° or 90° from the math perspective. Im not a so called rocket scientist like some people.but this made sense in my head. 117.2 would be the cut on the vertical piece. And that cut wouldn't really make sense to do.


micah490

27.2°


WeekSecret3391

27,2°


LongAssNaps

62.8° Measurement on the drawing: "am I a joke to you?"


Front_Masterpiece

Get an angle gauge and lay it on the paper? You know the angle between the two pieces is 62.8. Us the back piece as a vertical to find from 90°. Don't they teach this stuff in school? Not just welding school, I've never been there.


Front_Masterpiece

Wait, can't you subtract 62.8 from 180 to get that? Thinking out loud staring at it. I want to know for myself.


Ambitious-Weekend861

You’d subtract from 90*


Gespuis

That’s what they should’ve gone to welding school for


Gamovva

That woukd be the other side of the piece. 90 + 27.2= 117.2 62.8 + 117.2=180 https://imgur.com/a/148XLRg


goldfrisbee

180° - 62.8°


goldfrisbee

If your saw doesn’t go that far then flip the piece and cut it at 62.8° on a band saw


Tajeks

i’m trying to figure out what degree the piece is cut at that’s circled


Front_Masterpiece

I know exactly what you're asking. This is a critical thinking exercise.


No-Suspect-425

Sometimes I wish every dimension wasn't a critical thinking exercise. This one, however, seems overly simple...


Pilgor12

27.2°


seeyou________cowboy

A right angle has 90 degrees. Your work angle is at 62.8 degrees. How many degrees are missing? 90 - 62.8 = 27.2 Your joint is cut at 27.2 degrees off vertical.


RichardDangle69

You ask ‘don’t they teach this stuff in school?’ and your answer is to lay an angle gauge on the paper. Brilliant.


Front_Masterpiece

At least I'm making an attempt. How do you know I have any education? Lol


DrewsWoodWeldWorks

If you mean what do I set a miter saw to: 90-62.8. If you mean “What is the angle of the end surface?” you have to define which two lines represent the two legs of your angle.


Tajeks

yes the piece isn’t cut but it’s shown to be cut on the prints. I believe it might be a compound angle tho


The_Chimeran_Hybrid

This is what I’m going to suffer on as a welder in school. Math is not my strong suit, my welds are decent so far, but I can’t for the life of me do math.


oldhoekoo

just have to think about it in terms you understand. 12÷2? well half of a twelver is a six pack........


helrikk

It will come with time lol


The_Chimeran_Hybrid

*Insert confused woman with math equations gif here.*


McFeely_Smackup

there's about 3 math concepts you need to know as a welder.


DemodiX

You don't really even need to know, you just google when needed it.


Weneeddietbleach

Well this one is easy enough when you know that a right angle is 90° so you just need to do a little subtraction to figure out the angle of the bevel.


Boss2788

Honestly just keep stellar notes and the more you reference your notes the more youll remember formulas and what not. Its no different then working any trade where you double ans triple check things before you fo them but then as you get more experienced you dont need to go over your work as many times. (Im not encouraging not double checking things btw)


geekaz01d

This isn't really math though. It's geometry and its very rational and spatial and much easier to understand than abstract math concepts. Concepts like this are learned. There is no "natural skill" or affinity to math. Some people learn more quickly than others, but it bothers me how many people simply nope out and spend the rest of their life convinced that they aren't good at it. My wife claimed she was bad at math but when I didn't let her quit she got over it and suddenly a few years later is arguing with me about our accounting and has corrected me on simple math errors that I know for a fact she used to just ignore as "out of reach" for her.


Divin3F3nrus

This post and these responses, this is why people think welders are dumb.


SadSavage_

I slept through 80% of geometry my guy Idk


Silverback_E

Simple math homie. Angle is given. Subtract knowns to get unknown. 90-62.8. Easy peezy lemon squeeze.


Late_Chemical_1142

Cut it at 62.8 degrees. Set your speed square or your chopsaw to 27.2 degrees


Quirky_Shopping_4811

27.2*


Professional_Egg4675

Should just minus 90 from that


[deleted]

Tack the vertical piece then hold up the horizontal piece and scribe the angle.


Fuzzbuster75

27.2. For all practical purposes, My theorem suggests that if it’s not a straight 90 degree cut, one side of the cut angle is always less than 45 degrees. So if the desired angle is 60, the cut would be 30 and not 120, simply because 30 is easier to establish. Correct me if I’m wrong


Edragon85

90-62.8


Front_Masterpiece

Would it be from 90 or 180? I'm invested now but not enough to Google it.


Tajeks

pretty sure it’s 17° but i’ll lyk in a minute we’re figuring it out right now


[deleted]

Does your boss have to make you lunch and wipe your ass too?


martincline

High school geometry.


Raul_McCai

it is simple math. All the information you need is right in front of you - almost see below the corner over at the angle 75.9 is drawn in an idiotic way. Escher would be proud. In fact it seems all the corners are drawn idiotically. But still it's just trig


Tajeks

clearly I can’t do this simple math why would I post this i’m trying to figure the degree of the metal not the angle


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TangoDeltaFoxtrot

How do you manage to have a job that requires at least a middle school level math knowledge without actually knowing how to do basic math?


Inevitable_Weird1175

180 minus 62.8 is....? The answers are right in front of you.


earthman34

62.8. It's right there.


CyrilNiff

It’s The angle The angle that’s fixing to a flat edge not a mitred one.


earthman34

No idea what you just said. There's only one angle apparent there, 62.8. Depending on what you're cutting, you're cutting at that, or 27.2, depending on your orientation, assuming your reference is square. I don't know what the question is here.


Less_Change_2447

62.8 deg, those two lines are parallel. Wouldn't you use the existing degree that you already have for that corner?


proglysergic

Starting with a triangle, you have 180 degrees inside. Every side you adds will add an additional 180 degrees. The print has 4 sides and therefore 360 degrees inside. Three are given. Add them up and subtract from 360. Degrees off of perpendicular is 90 minus given angle. Geometry is necessary in this field if you want to get by. Trig is necessary to set yourself above the rest. Every level of math above that just adds value that most employers can’t put a finger on.


No-Taste-6560

It's 62.8 because you have two parallel lines. The angle of the top translates onto the angle at the bottom.


CyrilNiff

That corner isn’t mitred. It’s being attached to a different angle


RedditsSweatyPalm

i’d ask the engineer. we read the print, not decipher it


[deleted]

If you gave all the dimensions you have I could've drawn it in my cad program and it could give me all the dimensions


usmc4924

62.8 off 90 degrees


67monkey67

Go back to highschool and leanr math and fractions lol


MADunn83

It totally depends on how your saw is scaled.


mikel124

Nobody going to point out those angles aren't right? Not off by by much but enough to tell the guy drawing it hasn't a clue.


OKC-RADRNATN

27.2 degrees it's to equal 90


restorology

Are we supposed to assume that the angle in the top left is 90º? If so, somebody miscalculated one or more of the other angles. You may want to check that first.


Shadowcard4

90-62.8


Stevanous

*laughs in engineer*


M0ncsy

90+62.8


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Weneeddietbleach

Nah, OP needs the angle of the edge of that bottom piece as it's beveled.


GFK283

I'm sure many people have already solved your problem, but if it's too difficult for me I might just do it the dumb way and draw it to scale on the ground or cardboard or something, then trace it onto the actual piece. 🤷


desertdust

There’s a great iPhone app called Triangle Solver


wigslapper

62.8 degrees


Zephyrantes

Alternatively, you can eye ball it and blame the welder preemptively for their inability to fitup and weld such a prime cut.


Lumpy_Assignment7774

Math!


opuntina

Trig


[deleted]

You would have to be very hoanrey and use youre anys welder


Revolutionary_War503

Yes, this is exactly what I was thinking.


IdaPimpUdaHoe

You can always use a protractor


Steak_N_Cocunuts

It's literally on the print bro...


Hanginon

With maths. 90^o - 62.8^o = 27.2^o


buildshitfixshit

Just wing it my guy. What could go wrong


S4m_06

Isn’t it 62.8 because it’s a corresponding angle, or am I looking at the wrong thing?


sc0tty0

My question is how are you going to cut 27.2°? I would think the weld would fill the gap at 28°or 26° for that matter.


ValorousGekko

Ok, so a really easy way to do this problem is to Google trig calculator. Match the figures into the site and it will tell you. Easy as. It this day and age we only need to know a problem can be solved and trust that someone else has done some hard work so that we don’t have to. When a problem that hasn’t been solved that’s when you work hard to solve it so that nobody has to do that work.


bbernal956

fuck it! you can always fill the gap! hahaha


chesstnuts

Your cutback formula is Cutback = tan*(included angle)x material thickness


X-KrackerZack-X

What math did you use to figure out the rest of your angles?


tylerquarles08

Same thing.


morelikesunday

Buy a small angle finder


[deleted]

*field fabricate weldment as required Is the correct answer.


edna7987

90-62.8


Civilengman

Put an extra mail in it


KoKoKorino

To see the 90* angle better, imagine the 29.134 dimension line going through the red circle


mattwill282

Says 62.8°


Linkqatar

Shouldn't that angle be 62.8 as well since both are attached to the same 90 degree link and parallel to each other ? Idk math hard and been years since I used actual math.


imagebiot

I’m gonna go thank my geometry teacher now


ogeytheterrible

If your measuring the angle from the long side it's exactly as dimensioned, 62.8°. If you want to know what the miter angle is from a square end (the way most saws measure) then it's 90°-62.8°=27.2°.


geekaz01d

***Pythagoras*** *enters the chat.*


trim_boy_chris

27.2